No backwards running, although in the demo the character looked like he was quite fast while backpedaling :shrug:. I think they also said that you can stumble and fall if you get hit while backpedaling.
And what JOG said, no spellmaker. That means most likely no weakness stacking possible.
That's all the exploit fixes I know about so far.
Games always have exploits when they're first released. Since we don't know what the exploits may be in Skyrim, it's impossible to know how they'd be "fixed" already.
He was obviously talking about the gazillion exploits that were present in Oblivion.